Stock Investors See Slimmer Pickings

Stocks at Loftiest Levels in Years Compared With Profits

Some investors warn that the air is getting thinner for U.S. stocks, which head into the fourth quarter up 18% for the year and at their loftiest levels in years compared with corporate profits.

The Dow Jones Industrial Average advanced 1.5% during the third quarter even as economic growth remained uneven. The resiliency of the stock market's rally prompted several Wall Street strategists to throw in the towel on negative...